Technical Field
The present invention in particular embodiments relates to Gifford-McMahon (GM) cryocoolers.
Description of Related Art
GM cryocoolers, which are typifying examples of cryogenic refrigerators, generate extremely low temperatures using the GM cycle. That means that GM cryocoolers are configured so as to appropriately synchronize periodic pressure fluctuations in the expansion space—deriving from intake of the working gas into, its adiabatic expansion in, and its exhausting from, the expansions space—with periodic variation in volume of the expansion space due to the reciprocating movement of the displacer.